Electric motor fuel pumps are commonly used to supply the fuel demand for engines in a wide variety of applications. The electric fuel pump is known to be integrated into an in-tank fuel pump module typically having a filter at the pump inlet, a check valve at the pump outlet and a pressure regulator, downstream of the outlet check valve, for controlling fuel pressure at a fuel rail or fuel manifold mounted to the engine of an automotive vehicle. A support structure of the module usually includes a flange mounted sealably to the fuel tank and a reservoir can defining a reservoir. The fuel pump is usually located in the reservoir and draws fuel therefrom. The reservoir receives fuel from the surrounding, and much larger, fuel supply chamber defined by the fuel tank.
The reservoir provides a reliable source of liquid fuel for the fuel pump even when the larger fuel chamber is relatively low of fuel and/or when the fuel within the supply chamber sloshes about due to movement of the vehicle or any other dynamics occurring relative to the combustion engine. A jet pump assembly is typically used to maintain adequate fuel levels in the reservoir by routing a minority portion of fuel from the electric pump outlet and sending it through a venturi tube which in-turn aspirates a much greater amount of fuel from the fuel tank and into the reservoir. The jet pump assembly functions continuously regardless of reservoir fuel level and regardless of the fuel pressure at the pump outlet or pressure at the fuel rail. Unfortunately, during degraded or harsh conditions such as cold engine starts or substantially low voltage conditions, the electric motor fuel pump may not be capable of operating at full speed. When the electric pump operation is impaired, a potential exists that the engine may be starved of fuel during cold engine starts and/or low voltage conditions.